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    Quote Originally Posted by Ralph B View Post
    @billhingeJust wondering why you would use video mode for astro pictures. Seems like you should shoot in still mode for the highest quality. And perhaps use the 40 frame burst mode for bright objects.
    Not a silly question.

    Deep sky images like star fields do tend to contain stars and nebula which are generally faint and in the case of stars they are point objects. Here the name of the game is to take multiple single frames and stack them using clever software. Pro's would used peltier cooled ccd astrocameras but they are expensive, fortunately DSLR's hold up reasonably well except the normal canon/nikons usually have fairly severe internal UV/IR cut filters to maintain sharpness. The GH2's internal filter is lazy being sensitive to some uv and ir which softens the image. Adding an external UV/IR cut with a narrower range sharpens the image (on GH2 - works on cameras with weak internal filters) and improves the colour, drawback is that a decent filter is expensive.


    Anyway, planets and the moon differ because they are much brighter, have a visible area rather than point image. Being bright they only need a short exposure e.g. Mars through a telescope could be 1/100s @iso160 fl=2800mm f10. The images are tiny though, typically jupiter will cover approx 100 pixels on the GH2, so surprisingly shooting at 640x480 produces a larger looking imageNow the problem is that the atmosphere causes the image to literally boil at such a high magnification e.g. few hundred to even x1000. But for say approx 1/100 of a second every second we may some useful info the rest being garbage as the atmosphere steadies briefly.

    If you shoot as many 640x480 frames in say 3 minutes as you can at the highest possible data rate without compression you just might get some useful data (individual still image will still look crap) but by using special stacking software you take say 400 to a thousand of the best and stack them and a useful still image appears. Then using other software such as deconvolution, wavelets etc to post process to bring out hidden detail, so really its collecting 'bits' of data and averaging not video as you would think of it(each data compression
    negatively affects the final result thats why dedicated planetary cameras would use a small 640x480 ccd)hope that makes sense

    here are some stacked images (split into raw images, rgb channels and combined)
    Attached Images Attached Images
    Last edited by billhinge; 05-30-2012 at 02:59 PM. Reason: format was screwy, not as typed


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    Got it. Because of atmospheric blur in ground based astro pictures, I doubt the difference between the GH2's HDMI picture and an intra hack would be noticable. In other words, the atmosphere is the limiting factor, not the codec. My guess is you will get identical results wth both.


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    Thanks Ralph

    I'll spend my money on eyepieces then, cheaper ;-)

    I'm using your sanity hack now, I wasn't when doing the above images - due to the weather and work I haven't had time to try it out yet
    Last edited by billhinge; 05-31-2012 at 04:46 AM. Reason: additional info added


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    Senior Member Gabel's Avatar
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    I use the GH2 with a Ninja. Works great (as I only shoot in 25p, being European), however, you still have chroma issues. My problem is that I (like many other professionals) use a Mac.
    Right now I'm using this plugin:
    https://sites.google.com/site/hsgh2chromafix/

    But would much prefer to have it in Premiere instead (anybody know if it could be ported easily) or even better... Does anybody have a solution to get the AVIsynth working on a Mac? I've tried WineBottler, but the software doesn't install properly it seems. Help much appreciated!
    Help support my Lovecraft inspired 80s horror film I'm DPing on 16mm:
    http://www.indiegogo.com/insanemadness
    http://www.facebook.com/insanemadness2012

    Gabriel de Bourg Cinematography
    www.gabrieldebourg.se



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    In the first post, I added a link to a page with tons of Avisynth filters. Although these filters are not specifically related to the GH2 problem, they show the power of Avisynth, and why it's not a bad idea to learn to use it.

    http://avisynth.org/mediawiki/External_filters


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    Maybe a bit off topic, but I am still confused... So HDMI out is ALWAYS 1080i. But - to what video formats I am limited (I mean written to SD card, not on HDMI out) while using external HDMI monitor? ETC doesn't work, 720p is also dissabled when HDMI is plugged in. Anythig else?


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    Quote Originally Posted by valdi99 View Post
    Maybe a bit off topic, but I am still confused... So HDMI out is ALWAYS 1080i. But - to what video formats I am limited (I mean written to SD card, not on HDMI out) while using external HDMI monitor? ETC doesn't work, 720p is also dissabled when HDMI is plugged in. Anythig else?
    Yes, you can't use focus assist when the HDMI port is in use. But, you can use any of the 1080 shooting modes (with the exception of ETC).


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    Hello, please can someone help me to get this scrip running. I get errors:

    I have installed.
    Avisynth_258.exe
    Put all the extra plugins into the folder

    avisource("C:\Users\WRK-001\Desktop\GH FIX\cam_1.avi")

    LoadPlugin("C:\Program Files (x86)\AviSynth 2.5\plugins\TIVTC.dll")
    LoadPlugin("C:\Program Files (x86)\AviSynth 2.5\plugins\FDecimate.dll")
    LoadPlugin("C:\Program Files (x86)\AviSynth 2.5\plugins\mvtools2.dll")

    function filldrops (clip c)
    {
    **even = c
    **super_even=MSuper(even,pel=2)
    **vfe=manalyse(super_even,truemotion=true,isb=fals e,delta=1)
    **vbe=manalyse(super_even,truemotion=true,isb=true ,delta=1)
    **filldrops_e = mflowinter(even,super_even,vbe,vfe,time=50)

    **ConditionalFilter(even, filldrops_e, even, "YDifferenceFromPrevious()", "lessthan", "1.3")

    }


    # 3:2 Pulldown Removal
    AssumeTFF()
    trim(1,0)
    TFM(mchroma=false)
    FDecimate(threshold=0.5)
    AssumeFPS(24000,1001)

    # Chroma Fix
    FixBrokenChromaUpsampling()
    converttoyv12()

    # Fix Residual Duplicates
    filldrops()

    #Audio Delay
    delayaudio(.07)

    # Show the Metric for filldrops
    # This is a diagnostic to determine the threshold "lessthan" in the ConditionalFilter
    # To run, remove the # in the line below and put a # to the left of filldrops() 7 lines above
    # ScriptClip(last,"Subtitle(String(YDifferenceToNext () ))" )
    When I run the scrip I get (drag and drop to virtual dub) I get this error:

    Untitled.png

    ---------- Extra Notes ----------

    Ok. I am not using the Ninja, I am using the MX02. Here is the problem I have: http://www.youtube.com/watch?v=SmYKFCD_vwc. In other words I am happy with everything else except for the lack of smoothness. Is this becuase of the 4:2:2

    Please can someone help. I am willing to make a donation as I have spend 4 days none stop with no solution.


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    @bushidowarrior

    You're capturing on a Mac and using Prores. This is a Quicktime file, so in the script you need to change 'avisource' to 'qtinput'. You also need to install Apple's ProRes decoder for Windows. Put the qtsource.dll in your Avisynth plugins folder, and all should be fine.


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    Over 5 years - 200,000 hits - and still going...


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